This invention refers to an arrangement for embroidery machines, or similar machines, especially for area embroidery machines, in which the yarn ends which have to be fed in on the needle side must be changed when the yarn feeding system has run empty or, in the case of change of the embroidery pattern, when all or only some of the embroidery stations must be changed.
In shuttle type embroidery machines double T spools with relatively small amounts of yarn are used because the space available on the machine is not adequate for larger spools. Moreover, larger spools are associated with problems of maintaining the constancy of the yarn tension for the embroidery machinery (progressively decreasing weight and diameter). The feeding movement of the spools promotes the associated loop and knot formation and it is not possible to avoid the sudden jumping off of whole layers of yarn due to the jerky yarn take up of the embroidery mechanism.
Owing to the low yarn volumes of individual spools, conventional embroidery machines need a great deal of personnel expenditure and time for the change of needle yarns and this is associated with frequent standstill of the machines. The standstill can last up to 7 hours in any single instance for machines with 1,000 embroidery stations and will require employment of a large number of persons and this can occur on average, several times per week. Since the embroidery technique requires permanent change of patterns, and variations of the appearance of the product are absolutely necessary by changing the needle yarns, this operation, therefore, in conjunction with the required standstill of the machines, forms quite an appreciable cost factor.
It is seen from the above that, owing to the restricted space on the embroidery machine, a large number of spools of yarn is required and hence only a very small amount of yarn can be made up for use on the machine. The result of this arrangment is that in the first place small quantities of yarn have to be made up in a previous intermediate working process, which once again leads to increased costs. Moreover, the yarn sets which are lifted from the embroidery machines will, if used again, inherently lead to damage of individual spools of yarn resulting in new sources of embroidery defects which become effective later.